Gas-blast electric circuit breaker



Nov. 23, 3.948c D. F. AMER GAS-BLAST ELECTRIC CIRCUIT BRBKER 4 Shania-Sheet 2 Filed Dec. 6, 1946 Nov. 23, 1948. D. F. AMER 2,454,586

GAs-BLAsT ELECTRIC CIRCUIT BHEAKER 4 Sheets-Sheet 2 Filed Dec. 6, 1946 F765- Rl 2 R 2 HG2. R R l c E' 4e B361 B/ o y 5 a2 4 522 $2 R A #5A Inventor DI d? Mu/.1

By LUM, M, M PMM A Harney Nov. 23, 1948. D. F. AMER 294,535

GAS-'BLAST ELECTRIC CIRCUIT BREKER Filed DGO. 5 1946 4 ShSeS-Shee 5 A Homey Nov. 23, 1948.

4 Sheets-Sham Filed Dec. 6, 1946 Inventor A ltorney Patented Nov. 23, 1948 GAS-BLAST ELECTRIC CIRCUIT BREAKER Donald Foster Amer, Newcastle-on-Tyne, England, assignor to A. Reyrolle it Company Limited, Hebbnm-on-Tyne, England, a company of Great Britain Application December 6, 1946, Serial No. 714,598 In Great Britain December 18, 1945 (Cl. D- 148) 20 Claims.

This invention relates to gas-blast electric circuit-breakers of the kind comprising two relatively movable main contacts, a nozzle or vent associated therewith and a gas delivery chamber or reservoir on the high pressure side of the nozzle so that when a gas blast orifice at the outlet of an exhaust chamber or passage on the low pressure side of the nozzle is opened, a blast of deionising gas contained in or delivered to the delivery chamber or reservoir flows through the nozzle and thus assists in extinguishing the arc initiated between the separating contacts.

A gas-blast circuit-breaker according to the present invention is Provided with an exhaust orifice in tandem with the blast orifice, the circuit-breaker contacts, blast orifice, and exhaust orifice being so controlled sequentially by one and the saine control device that, duringppening of the circuit-breaker, the blast orifice is opened before the exhaust orifice is closed and, during closing of the circuit-breaker, the exhaust orifice is opened before the blast orifice is closed.

Preferably, the blast orifice and exhaust orifice respectively constitute the gas inlet and outlet of an expansion chamber so that, during opening of n the circuit-breaker, pressure gas will flow past the contacts into the expansion chamber and the build-up oi baci: pressure within the exhaust chamber will be delayed until after the arc has been extinguished, Whereas during reclosing of the circuit-breaker free flow of pressure gas past the contacts will only occur for the brief period while both the orifices are open, the pressure within the exhaust chamber being restored substantially immediately after the blast orifice is closed, whilst the gases within the expansion chamber, from the previous opening of the clrcuit-breaker, are discharged to the atmosphere. It will be apparent that, with this arrangement the major part of the exhaust gas is not discharged to the atmosphere duringopening of the circuit-breaker, but is held in the expansion chamber until the commencement of the next closing operation thus allowing adequate time for cooling of the gas before final discharge.

Instead of the gas i'low being throttled by at least one of the relatively movable contacts lying within the nozzle, these contacts may be ar'- ranged wholly outside the nozzle, the ow of gas being throttled by the restricted cross-section available for the flow of gas through the nozzle. The blast orifice and exhaust orifice may be controlled respectively by a blast valve and an exhaust valve, the two valves and the circuitbreaker contacts being operated sequentially by the one control device.

In one arrangement, the exhaust orifice constitutes the gas discharge port of a gas-tight casing enclosing the gas delivery chamber or reservoir, the circuit-breaker contacts, exhaust chamber or passage and the means for controlling the contacts and the gas blast and exhaust orifices Within the said casing. The single control device may then be connected to the control means within the casing through an operating spindle extending through theexhaust orifice, the necessity ior providing the control means with any gas-tight glands or other sealing joints against leakage to atmosphere, being thus wholly obviated.

Conveniently, the flow of gas through the nozzle or vent is strangled or throttled when the blast oriiice opens, so as to promote a depression on the exhaust side of the nozzle during separation of the contacts. To this end, the flow of gas through the nozzle may be throttled by at least one of the relatively movable contacts lying within the nozzle when the circuit-breaker is in the closed condition.

The nozzle or vent may comprise two aligned apertures formed respectively in opposite walls of an exhaust conduit in open communication with and supplementing the volume of the exhaust chamber, at least one of the relatively movable contacts extending into the nozzle when the circuit-breaker is in the closed condition. If desired two or more'such nozzles may be arranged in alignment, the several nozzles being in open communication with the exhaust chamber through separate exhaust conduits respectively. Whether one or a plurality of nozzles is employed, however, the arrangement is conveniently such that, during opening of the circuit-breaker'.A

the blast orifice is opened before the nozzle or nozzles is, or are, vacated by the contact or contacts, so that the depression in the exhaust chamber is accentuated before the contacts separate.

The invention may be carried into practice in various ways but three convenient practical arrangements, each according to the invention, are shown somewhat diagrammatically and by way of example, in the accompanying drawings, in which Figure 1 shows the circuit-breaker partly in vertical section,

Figures 2 and 3 are diagrammatic representations indicating the sequence of operations.

ananas ally between a fixed plug-like contact K1 and a longitudinally movable rod-like moving contact K. The opposite walls of the conduit J are fu'rnished respectively with two vents or nozzles JJ, J* lying in axial alignment with each other and with the two cooperating contacts K, K1. The two poles of the circuit-breaker, for example carried by bushing insulators M, M1 of the plug-in type, extend through the wall of the gas delivery chamber or reservoir L to the cooperating contacts K, K1 respectively, the xed plug-like contact K1 being conveniently electrically connected to the lateral conduit J2 oi' the exhaust chamber J through a limiting resistance M1.

With this arrangement, when the circuitbreaker is open as shown in Figure 4, the exhaust valve H1 in the expansion chamber H is closed whilst the blast valve J1 between the expansion chamber H and the exhaust chamber J is open, the gas delivery chamber or reservoir L being then in open communication through the vents or noz zles J3, J4 with the interior of the exhaust chamber J and expansion chamber H. When the control shaft F is operated to close the circuit-breaker the exhaust valve H1 is opened so that the gas within the chamber H is discharged to the atmosphere whereupon the rod-like contact K enters the aligned vents or nozzles J3, J4 and the blast valve J1 closes, the rod-like moving contact K then passing through the two aligned vents or nozzles J3, J4 and into engagement with the cooperating iixed plug-like contact K1. As with the construction irst described, when the circuitbreaker is opened, the blast valve J1 is opened before the exhaust valve H1 is closed, whereupon the gas within the exhaust chamber J expands into the expansion chamber H, the presence of the moving contact rod K within the nozzles or vents J3, J4 throttling the now of gas from the gas delivery chamber L into the exhaust chamber J. As the moving contact K is withdrawn from the nozzles or vents J3, J4 a blast of deionising gas ilows through the nozzles from the gas delivery chamber L until the pressure within the exhaust chamber J and expansion chamber H are again restored to that within the gas delivery chamber L.

In the construction shown in Figure 5, which shows the invention as applied to a circuitbreaker of the open type, the expansion chamber N is again mounted on a vertical hollow post insulator O as described with reference to the iirst arrangement, the expansion chamber N and the gas delivery chamber P being arranged one above the other upon the vertical post insulator O. Arranged at the upper end of the gas delivery chamber P is a further hollow insulating chamber Q carrying the iixed contact Q1 at its upper end with the interior of this insulating casing Q in open communication with the gas delivery chamber P. The vertical moving contact rod R is actuated from the stem S1 of the blast valve S through is/R toggle mechanism S? disposed wholly within the gas delivery chamber or. reservoir P, the upper end of the moving contact rod R cooperatingwith the vents or `nozzles R1 arranged in opposite walls of a plurality ot lateral conduits R in open coxn`l munication with, and supplementing the volume of, the exhaust chamber T. The operation of this construction is similar to that described with reference to Figure 4 except that the moving contact .rod R, instead of cooperating with a single pair of vents or nozzles of one lateral exhaust conduit, cooperates with a plurality of aligned pairs of such nozzles R1, each pair being formed in2 opposite walls oi. a separate exhaust conduit In the modiiied construction shown in Figure 6, the circuit-breaker contacts V, V1 cooperate wholly'outside the nozzle W so that the ilow of gas is throttled by the restricted cross-section available for the flow of gas through the nozzle W when the blast'valve X opens, thereby promoting a depression in the extension Y1 of the exhaust chamber Y during initial separation 0i' the contacts V, V1. As in Figures 4 and 5, the contact V, blast valve X and exhaust valve Y2 are operated through toggle mechanism X1 and Y3 from a single control rod Z.

Though in each of the above constructions the ilow of gas from the gas delivery chamber or reservoir to the exhaust chamber is restricted by at least one contact extending into the nozzle, this arrangement may be modied by arranging the contacts wholly outside the nozzle and within the delivery chamber, the throttling oi the gas ilow from the delivery chamber to the exhaust chamber being then produced solely by the restricted cross-section ariorded to such flow by the open nozzle. 1'

It will be understood that the constructions described above are given by way of example only and that details may be modied to suit requirements.

For example, the gas delivery chamber or'reservoir may either be maintained filled with gas under pressure or the gas may be delivered to the said reservoir or chamber only when the circuitbreaker is to be opened. For example, as shown in Figure 6 an inlet control valve Z1 may be provided Which is opened (e. g. automatically under fault conditions) by an auxiliary cam Z2 on the single control shaft before this operates the blast valve X and exhaust valve Y2.

What I claim as my invention and desire to secure by Letters Patent is: Y

1. A gas-blast electric circuit-breaker comprising a pressure-gas reservoir communicating with a gas delivery vent, two relatively movable main contacts cooperating at said vent, an exhaust chamber on the outlet side of the vent, said exhaust chamber having an outlet or blast orifice therein, a blast valve controlling the blast oriilce, opening of the blast valve thus causing a blast of deionising gas to flow from the reservoir and through the vent into the exhaust chamber, thereby assisting to extinguish an arc initiated between the main contacts, a passage communieating with said exhaust chamber through the blast orifice and having an outlet or exhaust orifice therein, an exhaust valve controlling said exhaust orice, the blast valve and exhaust value being thus disposed in tandem. and a single control device Whereby the main contacts, blast valve and exhaust valve are sequentially controlled. operation of said control device to open the contacts causing the blast valve to be opened before the exhaust valve is closed, whereas operation or said device to close the contacts causes the exhaust valve to be opened before the blast valve is closed. v

2. A gas-blast electric circuit-breaker comprising a pressure gas reservoir communicating with a gas delivery vent, two relatively movable main contacts cooperating at said vent, an exhaust chamber on the outlet side of the vent, said exhaust chamber having an outlet or blast orifice therein, a blast valve controlling sald blast orifice, opening oi said blast valve thus causing a blast of deionising gas to i'lovv from the reservoir and through the vent into the exhaust chamber thereby assisting to extinguish an arc initiated between .the main contacts, an expansion chamber communicating with said exhaust chamber through the blast orifice and having an outlet or exhaust orifice therein, an exhaust valve controlling said exhaust orince, the blast valve and exhaust valve being thus disposed in tandem, and a single control device whereby the main contacts, blast valve and exhaust valve are sequentially controlled, operation of the said control device to open the contacts causing the blast valve to be opened before the exhaust valve is closed so that pressure gas flows through the vent past the separating contacts, and-through the exhaust chamber and expansion chamber to the atmosphere, the buildup of back pressure within the exhaust chamber being delayed until after the arc has been extinguished, whereas operation of the said control device to close the contacts causes the exhaust valve to be opened before the blast valve is closed so that free flow of pressure gas past the contacts will only occur for the brief period while both valves are open, the pressure within the exhaust chamber being restored when the blast valve has closed, whilst the gases within the expansion chamber, from the previous opening of the circuit-breaker, are discharged to the atmosphere past the open exhaust valve.

3. A gas-blast electric circuit-breaker comprising a pressure-gas reservoir communicating ywith s. gasdelivery nozzle,"two relatively movable main contacts cooperatingV at' said nozzle, an exhaust chamber on the outlet side of the nozzle, said A exhaust chamber having an outlet or blast'orice therein, a. blast valve controlling said. blast orice, opening of said blast valve thus causing a blast ot deionising gas to ilow from the reservoir and through the nozzle into the exhaust chamber thereby assisting to extinguish an arc initiated between the main contacts, an expansion chamber communicating with `said exhaust chamber through the blast orifice and having an outlet or exhaust orifice therein, an exhaust valve controlling said exhaust orice, the blast valve and exhaust valve being thus disposed in tandem, and a. single control device whereby the main contacts, blast valve and exhaust valve are sequentially controlled, operation of the said control device to open the contacts causing the blast valve to be opened before the exhaust valve is closed so that pressure gas flows through the nozzle past the separating contacts, and through the exhaust chamber and expansion chamber to the atmosphere, the build-up of back pressure within the exhaust chamber being delayed until after the arc has been extinguished, whereas operation of the said control device to close the contacts causes the exhaust valve to be opened before the blast valve is closed so that free flow of pressure gas past the contacts willonly occur for the brief period while both valves are open, the pressure within the exhaust chamber being restored when the blast valve has'clsed,whilst the gases within the .expansion chamber, from the .previous opening or the circuit-breaker, are discharged to the atmosphere past the open exhaust valver 4. A gas-blast circuit-breaker as claimed in claim l, in which the exhaustl orifice constitutes the gas discharge port of a gas-tight casing enclosing the reservoir, circuit-breaker contacts, exhaust chamber and the means for controllinghe contacts and the gas blast and exhaust oriiices.

'5. A gas-blast electric circuit-breaker comprising a pressure gas reservoir communicating with a gas delivery vent, two relatively movable main contacts cooperating at said vent, an exhaust chamber on the outlet side of the vent, said exhaust chamber having an outlet or blast orifice therein, a blast valve controlling said blastl orice, opening of said blast valve thus causing a blast of deionising gas to flow from the reservoir and through the vent into the exhaust chamber thereby assisting to extinguish an arc initiated between the main contacts, an expansion chamber communicating with said exhaust chamber through the blast orice and having an outlet or exhaust orice therein, an exhaust valve controlling sald exhaust orice, the blast valve and exhaust valve being thus disposed in tandem, a gas-tight casing enclosing the reservoir, circuitbreaker contacts, exhaust chamber, blast valve and exhaust valve, said exhaust orifice constituting the gas discharge port of .the gas-tight enclosing casing, and a single control device whereby the main contacts, blast valve and exhaust valve are sequentially controlled Within the casing, operation of the said control device to open the contacts causing the blast valve to be opened before the exhaust valve is closed so that pressure gasv flows through the vent past the separating contacts, and through the exhaust chamber and expansion chamber to the atmosphere, the build-up of back pressure within the exhaust chamber being delayed until after the arc has been extinguished, Whereas operation of the said control device to close the contacts causes the exhaust valve lto be opened before the blast valve is closed so that free flow of pressure gas past the contacts will only occur for the brief period While both valves are open, the pressure within the exhaust chamber being restored when the blast valve has closed, Whilst the gases within the expansion chamber, from the previous opening of the circuit-breaker, are discharged to the atmosphere past the open exhaust valve.

' 6. A gas-blast electric circuit-breaker as claimed in claim 5, in which the single control device is connected to the control means within the casing through an operating spindle extending through the exhaust orifice.

' 7. A gas-blast electric circuit-breaker comprising a pressure-gas reservoir communicating with a gas delivery vent, two relatively movable main contacts cooperating at said vent, an exhaust chamber on the outlet side of Ithe vent, said exhaust chamber having an outlet or blast orifice therein, a blast valve controlling the blast orice, opening of the blast valve thus causing a blast of deionising gas to flow from the reservoir and through the vent into the exhaust chamber thereby assisting to extinguish an arc initiated between the main contacts, a passage communieating with said exhaust chamber through the blast orice and having an outlet or exhaust orifice therein, an exhaust valve controlling said ,csasac exhaust orifice, the blast valve and exhaust valve being thus disposed in tandem, a gas-tight cas-1 ing enclosing the reservoir, circuit-breaker contacts, exhaust chamber passage, blast valve, and exhaust valve, saidy exhaust orifice constituting the gas discharge port of the gas-tight enclosing casing', and a single control device whereby the main contacts, blast valve and exhaust valve are sequentially controlled, operation of said control device to open thc contacts causing the blast valve to be opened before the exhaust valve is closed, whereas operation of said de vice to close the contacts causes the exhaust valve to be opened before the blast valve is closed. 8. A gas-blast electric circuit-breaker as claimed in claim 7, in which the single control device is connected to the control means within the casing through an operating spindle extending through the exhaust orifice. l

9. A gas-blast circuit-breaker as claimed in claim 1, having means whereby the flow of gas through the vent is throttled when the blast orifice opens, a depression on the exhaust side of the'vent being thus promoted during separation of the contacts.

aligned apertures formed respectively in opposite walls of the exhaust conduit and together constituting a vent through which the reservoir communicates with the exhaust conduit, two relatively movable main circuit-breaker contacts at least one of which extends into the vent when the circuit-breaker contacts are closed, a blast valve controlling said bast orifice, opening of' the blast valve thus causing a blast of deionising gas to flow from the reservoir and through the vent, as throttled by the said contact therein, into the exhaust conduit and exhaust chamber thereby assisting to extinguish an arc initiated between the main contacts, a passage communicating with said exhaust chamber through the blast orifice and having an outlet or exhaust orifice therein, an exhaust valve controlling said exhaust orifice, the blast valve and exhaust valve being thus disposed in tandem, and a single control device whereby the main contacts, blast valve and exhaust valve are sequentially controlled, operation of said control device to open the contacts causing the blast valve to be opened before the exhaust valve is closed, whereas voperation of said device to close the contacts causes the exhaust valve to be opened before the blast'valve is closed.

12. A gas-blast electric circuit-breaker comprising a pressure-gas reservoir, an exhaust chamber, an exhaust conduit in open communication with and supplementing the volume of the exhaust chamber which has an outlet or blast orifice therein, the exhaust conduit having two aligned apertures formed respectively in opposite walls of the exhaust conduit and together constituting a vent through which the reservoir communicates with the exhaust conduit, Vtwo relatively movable main circuit-breaker contacts at least one of which extends into the vent when the maincontacts, an expansion chamber com` the circuit-breaker contacts are closed, a blast valve controlling said blast orifice, lopening of the blast valve thus causing a blast of deionising gas to flow from the reservoir and through the vent, as throttled by the said contact therein, into the exhaust conduit and exhaust chamber thereby assisting to extinguish an arc initiated between the main contacts, an` expansion chamber communicating with said exhaust chamber through the blast orifice and having an outlet or exhaust orifice therein, an exhaust valve controlling said exhaust orifice, the blast valve and exhaust valve being thus disposed in tandem, and a single control device whereby the main contacts, blast valve and exhaust valve are sequentially controlled, op-

eration of the said control device to open the contacts causing the blastv valve to be opened before the exhaust valve is closed so that pressure gas flows through the vent pastthe separating contacts, and through the exhaust chamber and expansion chamber to the atmosphere, the buildup of back pressure within the exhaust chamber being delayed until after the arc has been extinguished, whereas operation of the said control device to close the contacts causes the exhaust valve to be opened before the blast valve is closed so that free flow of pressure gas past the contacts will only occur for the brief period while both valves are open, thegpressure within the exhaust chamber being restored when the blast valve has closed, whilst the gases within the expansion chamber, from the previous opening of the circuit-breaker, are discharged to the atmosphere past the open exhaust valve.

13. A gas-blast electric circuit-breaker as claimed in claim 11, in which the exhaust orifice constitutes the gas discharge port of a gas-tight casing enclosing the reservoir, circuit-,breaker contacts, exhaust chamber and the means for controlling the contacts and the gas blast and exhaust orifices.

14. A gas-blast circuit-breaker as claimed in claim 12, having a gas-tight casing enclosing the reservoir, circuit-breaker contacts, exhaust conduit, exhaust chamber, blast valve and exhaust valve, said exhaust orifice constituting the gas discharge port of the gas-tight enclosing casing.

l5. A gas-blast electric circuit-breaker comprising a pressure-gas reservoir, an exhaust chamber, an exhaust conduit in open communication with and supplementing the volume of the exhaust chamber which has an outlet or blast orifice therein, the exhaust conduit having two aligned apertures formed respectively in opposite walls of the'exhaust conduit and together constituting a nozzle through which the reservoir communicates with the exhaust conduit, two relatively movable main circuit-'breaker contacts at least one of which extends into the nozzle when the circuit-breaker contacts are closed, a. blast valve controlling said blast orifice, opening of the blast valve thus causing a blast of deionising gas to flow from the reservoir and through the nozzle, as throttled by the said contact therein, into the exhaust conduit and exhaust chamber thereby assisting to extinguish an arc initiated between municating with said exhaust chamber through the blast orifice and having an outlet or exhaust orifice therein, an exhaust valve controlling said exhaust orice, th'e blast valve and exhaust valve being thus disposed in tandem, a gas-tight casing enclosing the reservoir, vcircuit-breaker contacts, exhaust chamber, expansion chamber, blast valve and exhaust valve, said exhaust orifice constituting the gas discharge port of the gas-tight en-- closing casing, and a single control device whereby the main contacts; blast valve and exhaust valve are sequentially controlled within the casing, operation of the said control device to open the contacts causing( the blast valve to be opened before the exhaust valve is closed so that pressure gas flows through the nozzle past the separating contacts, and through the exhaust chamber and expansion chamber to the atmosphere, the buildup of back pressure within the exhaust chamber being delayed until after the arc has been extinguished, whereas operation of the said control device to close the contacts causes the exhaust valve to be opened before the blast valve is closed so that free iiow of pressure gas past the contacts will only occur for the brief period while both valves are open, the pressure within the exhaust chamber being restored when the blast valve has closed, whilst the gases within the expansioh chamber, from the previous opening of the circuit-breaker, are discharged to the atmosphere past the open exhaust valve.

16. A gas-blast circuit-breaker as claimed in claim 11, having at least two aligned vents, the several vents being in open communication with the exhaust chamber through separate exhaust conduits respectively.

17. A gas-blast circuit-breaker as claimed in claim 12,havingy at least two aligned vents, the several vents being in open communication with the exhaust chamber through separate exhaust conduits respectively.

claim 1. in which at least one of the main con- -12` 18. A gas-blast circuit-breaker as claimed in claim 15, having at least two aligned nozzles, the several nozzles being in open communication with ythe exhaust chamber through separate exhaust conduits respectively.

19.' A gas-blast circuit-breaker as claimed in tacts, when ln-its closed position, extends into the associated vent so as to throttle the gas ow open the contacts causing the blast orice to bef-1 opened before the nozzle is vacated by said contact, the depression in the exhaust chamber being thus accentuated before the contacts separate.

DONALD FOSTER AMER.

REFERENCES CITED .The following references are of record in the ille 'of this patent:

UNITED STATES PATENTS Number Name Date Kesselring Feb. 15, 1938 

